dekati application example: blow-by –measurement
TRANSCRIPT
Dekati® Application example: Blow-By –measurement(Crankcase ventilation)
A story...
• blowby filter efficiency measurements are needed to develop/verify filter performance
• Typical particle size and concentration? – 0.05 – 5 microns, 5-10 mg/m3
• HR/HT-ELPI+ wide size range, real-time data
High Temperature ELPI+™
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• Same operating principle as ELPI+™• Charger+Impactor moved to external heating unit, max 180 °C• Allows hot aerosol size and charge distribution measurement in real-time• Heater maintains temperature and avoids condensation, NO residence time to
heat up the sample
What is Blowby (crancase) emission?
• Most combustion gas in an engine exits the cylinder through a valve and then out the exhaust pipe
• A portion of the gas escapes through a gap between the piston wall and the piston ring, this is called blow-by
• Blow-by gases enter the crankcase chamber and exit through a breather tube – typically to engine intake
• There is oil mist (oil droplets) in blow-by gas• To avoid excess oil loss there is a usually a filter /
impactor / cyclone in the breather tube
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Why is it measured ?
• There is usually some oil separator in the breather tube – filter, impactor or cyclone
• Particle size is measured upstream and downstream of the separator to study and optimize its efficiency
• Customers are engine manufacturers (esp. HD) and filter manufacturers
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Crancase emission – particle size
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• Crancase oil droplets are relatively large (mass around 1 um) but there are lot of small particles as well including soot and ash that escapes the cylinder
Other crancase particle properties
• Oil droplets, wide particle size range• High concentration (milligrams / m3)• High temperature (100°C)• Slightly elevated pressure• Need to measure pre- and post oil separator
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Selection of ELPI+ configuration
HT-ELPI+ and Heated DI-1000
Why and what kind of ELPI+?
• Wide size range of ELPI covers both nano range where filtration efficiency information is important and micron range where mass emission (oil consumption) is important.
• ELPI+ can be heated so sampling is done at crankcase conditions
• HT-ELPI+ is the ideal instrument for this application
• Could be high concentration, one heated ejector diluter might be needed
• Sintered plates recommended
Existing data, articles and other information from Dekati
• Customer references – AGCO, Parker Hannfin, Caterpillar, Donaldson, ...
• Information about standards – Dekati is a member of ISO/TC22/SC34 WG 11:Filtration performance of closed
crankcase ventilation systems
• Example data:
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Basic configuration for Blow-By emission measurement
• HT-ELPI+• Heated DI-1000• Sintered collection plates
OR
• (HR)-ELPI+, Sintered plates• DI-2000 + DI-2003
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Thank you!
-Questions and discussion
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